Low Intensity Vibration Protects the Weight Bearing Skeleton and Suppresses Fracture Incidence in Boys with Duchenne Muscular Dystrophy

Abstract

Introduction/Aims: The ability of low intensity vibration (LIV) to combat skeletal decline in Duchenne Muscular Dystrophy (DMD) was evaluated in a randomized controlled trial. Methods: Twenty DMD boys were enrolled, all ambulant and treated with glucocorticoids (mean age 7.6, height-adjusted Z-scores (HAZ) of hip BMD -2.3). Ten DMD boys were assigned to stand for 10min/d on an Active LIV platform (0.4g @ 30Hz), while 10 stood on a Placebo device. Baseline and 14-month BMC and BMD of spine, hip and total body were measured with DXA, and trabecular bone density (TBD) of tibia with QCT. Results: All children tolerated the LIV intervention well, with daily compliance averaging 78%. At 14 months, TBD in the proximal and distal tibia remained unchanged in Placebo (-0.7% & -0.8%), while rising 4.1% and 4.5% in LIV. HAZ for hip BMD and BMC in Placebo declined 22% and 13% respectively, contrasting with no change from baseline (0.9% and 1.4%) in LIV. Fat mass in the leg increased 33% in Placebo, contrasting with 20% in LIV subjects. Across the 14-month study, there were four incident fractures in three placebo patients (30%), with no new fractures identified in LIV subjects. Conclusions: These data suggest that non-invasive LIV can help protect the skeleton of DMD children against the disease progression, the consequences of diminished load bearing, and the complications of chronic steroid use.